U.S. Pat. No. 8,062,170 discloses one exemplary motor control apparatus, which controls driving of a motor. In this motor control apparatus, for example, a maximum torque is attenuated in accordance with temperature before an electronic driving system for driving a motor reaches a critical temperature.
When torque of the motor is limited in accordance with temperature, sensitivity of torque relative to a temperature change increases. For this reason, when the maximum torque is changed in accordance with temperature even under a low temperature condition, the torque of the motor is likely to vary in accordance with temperature in high load operation time.